Hawaii is on a lot of people's travel bucket list. You may think sand beaches and volcanoes, but formations like this are breathtaking. What's your favorite thing about Hawaii? (Na Pali Coast Waterfall Cave, Hawaii)

Toketee Falls, Oregon (USA) by Skyler Hughes

{This is an ice cave, known as "crystal Cave" on the frozen lagoon of the Svínafellsjökull glacier in Skaftafell, Iceland. This snow, which is up to 1000 years old has metamorphosed into highly pressurized glacier ice that contains almost no air bubbles.

Eerie photo of the Yellow Brick Road from an abandoned Wizard of Oz theme park in North Carolina. Two cool ideas. One, find the broken down yellow road. Two, that there was a Wizard of Oz theme park.

Devil Spring - one of seven springs that are located in the private Ginnie Springs park (northern Florida), a cave divers paradise. For non-divers there is still plenty to see when snorkelling. The intense blue colour is due to the water depth at the cave